DE10239134A1 - Production of a saturated aliphatic 3-30C carboxylic acid, useful for the production of dyestuffs, comprises hydroformylation of 1-butene, cis-2-butene and/or trans-2-butene and oxidation - Google Patents

Abstract

Production of a saturated aliphatic 3-30C carboxylic acid comprises (A) optional metathesis and/or oligomerization of 1-butene, cis-2-butene and/or trans-2-butene to form 2-29C alkenes; (B) hydroformylation of 1-butene, cis-2-butene and/or trans-2-butene and/or the 2-29C alkenes from step (A) to form 3-30C alkanals; and (C) oxidation of the resulting 3-30C alkanals to form 3-30C carboxylic acids.

Description

The present invention relates to a process for the production of a saturated aliphatic C ₃ - to C ₃₀ -carboxylic acid or a mixture thereof using n-butenes by optional metathesis and / or oligomerization, hydroformylation and oxidation.

Saturated aliphatic C ₃ to C ₃₀ carboxylic acids are important end products and intermediates and are widely used. For example, they are used in hydraulic fluids, machine oils and cosmetic products. Their derivatives, for example esters or metal salts, are used in a variety of ways as solvents, flavors, fragrances, plasticizers for plastics, stabilizers, lubricants, fungicides and drying agents for paint systems. They are also valuable intermediates for pharmaceutical and agricultural ingredients, alkyd resins, corrosion inhibitors, detergents, oil additives, preservatives and cosmetic products.

A number of different processes are known for producing saturated aliphatic C ₃ -C ₃₀ -carboxylic acids. An overview of the various manufacturing processes can be found in Ullmann's Encyclopedia of Industrial Chemistry, 6 ^th edition, 2000 electronic release, chapter "CARBOXYLIC ACIDS, ALIPHATIC-Production".

For example, the medium chain carboxylic acids by reacting alcohols with alkali hydroxides at 250 to 300 ° C and about 2 MPa converted into the corresponding carboxylates which are treated with strong acids corresponding carboxylic acids can be released. Disadvantageous this procedure is poor availability respectively elaborate production of the corresponding operational alcohols, the drastic reaction conditions in the implementation as well as the cumbersome release of the carboxylic acids by the Acid treatment.

Furthermore, carboxylic acids can be oxidized by Alkanes, especially paraffins, paraffin waxes, polyethylenes and Extract polypropylenes with oxygen or air. Disadvantageous this process is the low selectivity in the oxidation, which results in the formation of a wild mixture of various carboxylic acids and in the formation of large amounts Carbon dioxide noticeable.

Of particular importance for the technical production of carboxylic acids Carbonylation of olefins and oxidation are important of aldehydes.

In the carbonylation of olefins, the corresponding Olefins with carbon monoxide and water in the presence of a Catalyst converted to the corresponding carboxylic acids. A A compilation of the carbonylation processes can be found in K. Weissermel and H.-J. Arpe, Industrial Organic Chemistry, 5th edition, Wiley-VCH, Weinheim 1998, pages 154 to 158. In the known Reppe carbonylation takes place in the presence of a reaction Metal carbonyls as a catalyst. As suitable metal carbonyls the carbonyls of nickel, cobalt, iron, Rhodium, ruthenium and palladium are used. Disadvantage of the Reppe carbonylation are the drastic required Reaction conditions, the low space-time yield and the fact that olefins with more than three carbon atoms due to the Double bond isomerization to a mixture of different Carboxylic acids lead and therefore not economically sensible is feasible. For example, carbonylation requires from ethene to propionic acid in the presence of nickel carbonyl Pressure from 200 to 240 bar and a temperature from 270 to 320 ° C. By using a palladium / phosphine containing In carbonylation, the catalyst is also a pressure range of accessible well below 50 bar. This is how EP-A 0 495 547 teaches its use of a catalyst containing palladium, a bidentate Phosphine ligands and a strong acid anion which Reaction at a pressure of 1 to 15 bar and a temperature from 50 to 150 ° C. This method is disadvantageous however, the tendency to deposit metallic palladium, so that the catalyst system after a short reaction time deactivated. The implementation takes place in the so-called cooking process of olefins in the presence of protonic acids at a pressure of about 20 to 100 bar and a temperature of about 20 to 80 ° C. A disadvantage of the cooking process is the fact that even when using linear, terminal olefins due to the Double bond and structural isomerization of only mixtures of isomeric, branched carboxylic acids arise.

In the oxidation of aldehydes, these are preferred in the Liquid phase with air or oxygen in the absence or in Presence of a catalyst to the corresponding carboxylic acids oxidized. If catalysts are used, they contain them predominantly metal salts of metal ions, which in different oxidation levels can occur. The oxidation takes place under mild reaction conditions, with atmospheric pressure and a Temperature up to 100 ° C is generally sufficient.

The aldehydes used in the oxidation of aldehydes are usually obtained by hydroformylation of olefins. The olefins used for the hydroformylation can be obtained by a large number of technical processes, as described, for example, in K. Weissermel and H.-J. Arpe, Industrielle Organische Chemie, 5th edition, Wiley-VCH, Weinheim 1998, pages 65 to 99. According to the cited reference, the unbranched higher olefins with more than four carbon atoms, in particular with a terminal double bond, can be obtained by ethene oligomerization or dehydrogenation of paraffins. The branched higher olefins with more than five carbon atoms can preferably be obtained by oligomerization and cooligomerization of lower olefins according to the cited literature reference. Combination processes for the production of higher olefins are also known. The process known as the SHOP process (Shell Higher Olefin Process) for producing C ₁₀ to C ₁₈ olefins includes ethene oligomerization, double bond isomerization and metathesis.

The object of the present invention was to find a process for the preparation of saturated aliphatic C ₃ - to C ₃₀ -carboxylic acids which does not have the disadvantages mentioned above and which is based on an easily accessible and economically attractive raw material base, a simple and inexpensive design of the apparatus entire system (low investment costs), is technically simple and safe to carry out in its entirety and enables a high yield and high space-time yield of the desired carboxylic acids.

• a) optional durch Metathese und/oder Oligomerisation in ein C₂- bis C₂₉-Alken oder dessen Gemisch überführt;
• b) das 1-Buten, cis-2-Buten, trans-2-Buten oder dessen Gemisch und/oder das C₂- bis C₂₉-Alken oder dessen Gemisch aus der optionalen Verfahrensstufe (a) durch Hydroformylierung in ein C₃- bis C₃₀-Alkanal oder dessen Gemisch überführt; und
• c) das C₃- bis C₃₀-Alkanal oder dessen Gemisch aus der Verfahrensstufe (b) durch Oxidation in die gesättigte aliphatische C₃- bis C₃₀-Carbonsäure oder deren Gemisch überführt.

Accordingly, a process has been found for the production of a saturated aliphatic C ₃ to C ₃₀ carboxylic acid or mixtures thereof, which is characterized in that 1-butene, cis-2-butene, trans-2-butene or a mixture thereof is used,

• a) optionally converted into a C ₂ -C ₂₉ alkene or a mixture thereof by metathesis and / or oligomerization;
• b) the 1-butene, cis-2-butene, trans-2-butene or its mixture and / or the C ₂ - to C ₂₉ -alkene or its mixture from the optional process step (a) by hydroformylation into a C ₃ - transferred to C ₃₀ alkanal or its mixture; and
• c) the C ₃ to C ₃₀ alkanal or its mixture from process step (b) is converted by oxidation into the saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture.

The 1-butene, cis-2-butene, trans-2-butene to be used or a mixture thereof can be the pure or largely pure isomeric n-butenes, a mixture of two or three n-butenes or a mixture of one or trade several n-butenes with other components. Other components which are particularly suitable are those which do not, or only insignificantly, interfere with the course of the reaction in the subsequent reactions and can be separated off without any great effort in the further course of the process, or in the end product, ie the saturated aliphatic C ₃ - bis C ₃₀ carboxylic acid or a mixture thereof can be tolerated. Saturated or unsaturated hydrocarbons may be mentioned as possible further components. The saturated hydrocarbons are generally not converted in the subsequent process stages and are generally separated off during the workup. Depending on how the reaction is carried out, the unsaturated hydrocarbons can also be reacted in the individual process stages. Depending on this, these can also contribute to the formation of valuable product or, in the case of formation of undesired products, can be separated off.

Mixtures are preferred in the process according to the invention Hydrocarbon streams containing n-butenes are used. Especially hydrocarbon streams which have a Total content of n-butenes (1-butene, 2-trans-butene and 2-cis-butene) of ≥ 10% by weight, preferably of ≥ 30% by weight and particularly preferably contain ≥ 50 wt .-%. The one containing n-butene Hydrocarbon stream can furthermore be aliphatic and aromatic, contain saturated and unsaturated hydrocarbons. As Examples include methane, ethane, ethene, propane, propene, n-butane, iso- Butane, isobutene, 1-pentene, 2-cis-pentene, 2-trans-pentene, n-pentane, cyclopentene, cyclopentane, hexenes, hexanes, cyclohexane and Called benzene.

In the process according to the invention, particular preference is given to using hydrocarbon streams containing n-butenes from natural gas, steam crackers or FCC crackers. The so-called C ₄ raffinate II stream, which is obtained from the raw C _{4 section} of steam crackers, is very particularly preferred. The C ₄ raffinate II stream is to be understood as the C ₄ stream in which 1,3-butadiene was largely removed or converted to n-butenes by selective hydrogenation and isobutene was removed. Its n-butenes content is generally from 50 to 95% by weight. A typical, non-limiting composition of a C ₄ raffinate II stream is given in Table 1: TABLE 1 Typical composition of a C ₄ raffinate II stream

The saturated aliphatic C ₃ - to C ₃₀ -carboxylic acid or its mixture is produced in the process according to the invention by stepwise reaction of the 1-butene, cis-2-butene, trans-2-butene or its mixture to be used in the optional process step (a) , process stage (b) and process stage (c).

Process stage (a) Metathesis / oligomerization

The optional process step (a) gives the possibility of using the unbranched C ₄ -alkenes, that is to say the 1-butene, cis-2-butene, trans-2-butene or its mixture, depending on the reaction procedure and combination of metathesis and Oligomerization to produce the C ₂ to C ₂₉ alkene required for the production of the desired saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture or its mixture in a targeted manner. In the event that the required C ₂ -C ₂₉ alkene or its mixture corresponds to the 1-butene, cis-2-butene, trans-2-butene or its mixture to be used, process step (a) can generally be omitted ,

The following are the metathesis and the Oligomerization of the optional process step (a) explained in more detail.

In the method according to the invention, the metathesis can generally be carried out in the manner customary and known to the person skilled in the art. A good overview with numerous further references is found for example in Ullmann's Encyclopedia of Industrial Chemistry, 6 ^th edition, 2000 electronic release, Chapter "HYDROCARBONS, olefin". Further information on the implementation of the method can be found, for example, from KJ Ivin, "Olefin Metathesis", Academic Press, London 1983 or RL Blanks, "Discovery and Development of Olefin Disproportionation", CHEMTECH 1986, February, pages 112 to 117. The information provided there enables the person skilled in the art to metathesize the butenes to be used and any alkenes formed therefrom by oligomerization.

Suitable catalysts are preferably molybdenum, tungsten or rhenium compounds. It is particularly expedient to carry out the reaction under heterogeneous catalysis, the catalytically active metals being used in particular in conjunction with supports composed of Al ₂ O ₃ or SiO ₂ . Examples of such catalysts are MoO ₃ or WO ₃ on SiO ₂ or Re ₂ O ₇ on Al ₂ O ₃ . It is particularly advantageous to carry out the metathesis in the presence of a rhenium-containing catalyst, since in this case particularly mild reaction conditions are possible. In this case, the metathesis can be carried out at a temperature in the range from 0 to 50 ° C. and at a pressure of approximately 0.1 to 2 MPa abs.

The metathesis gives an alkene mixture which Alkenes with smaller and with a larger number of carbon atoms than the starting material used. Depending on the requirement in the Subsequent stages it is possible and possibly advantageous that alkene mixture obtained in the desired fractions, for example, to separate by distillation.

The specific metathesis procedure to be carried out Conditions to be set and catalysts to be used can Expert can be determined in the usual way.

In the process according to the invention, the oligomerization can generally be carried out in the manner which is customary and known to the person skilled in the art. A good overview with numerous further references is found for example in Ullmann's Encyclopedia of Industrial Chemistry, 6 ^th edition, 2000 electronic release, Chapter "HYDROCARBONS, olefin". The information provided there enables the person skilled in the art to oligomerize the butenes to be used and any alkenes formed therefrom by metathesis.

The catalysts to be used are preferably heterogeneous and preferably contain at least one metal from the 8th to the 10th group of the periodic table. It is particularly useful Combinations of a metal from the 8th to 10th group of the periodic table with aluminum oxide on substrates containing silicon and Titanium oxides, as described for example in DE-A 43 39 713, use.

To achieve high sales, the reaction mixture in the Usually several times in a circle, with a continuous certain proportion of the circulating product is discharged and through further educt is replaced.

The oligomerization gives an alkene mixture which is predominantly alkenes with n times the number of carbon atoms, in terms of the number of carbon atoms in the educt alkene, contains, where n is an integer, positive number. Be predominant Alkenes with twice the number of carbon atoms as in Educt alkene formed, one speaks for example of one dimerization; are predominantly alkenes with three times the number One speaks of carbon atoms as formed in the educt alkene for example from trimerization. One is preferred Oligomerization in which at least 80% of the oligomerization product Dimers of the alkene used are.

Depending on the requirements in the subsequent stages, it is possible and possibly advantageous to separate the alkene mixture obtained into the desired fractions, for example by distillation. When carrying out the optional process step (a), it is possible in the process according to the invention to carry out only one of the two reactions mentioned, that is to say only the metathesis or only the oligomerization. In the metathesis of 1-butene, cis-2-butene, trans-2-butene or a mixture thereof, a C ₂ - to C ₆ -alkene mixture is obtained primarily, which, if appropriate, can be converted into the desired fractions or pure alkenes, such as about C ₅ alkene mixture, 2-pentene, C ₆ alkene mixture or 3-hexene, can be separated. When 1-butene, cis-2-butene, trans-2-butene or its mixture are dimerized, a C ₈ -alkene mixture is obtained primarily and a C ₁₂ -alkene mixture is primarily obtained during trimerization.

It is also possible to use metathesis and oligomerization direct or indirect (e.g. using a separated part from the first implementation stage) episode perform, with both the metathesis and the Oligomerization can be started. Furthermore, it is possible, both implementations several times in alternating sequence perform.

Dimerization is preferred in the process according to the invention from 2-pentene obtained by metathesis of n-butenes to one Decen mixture as well as the dimerization of by metathesis of n-butenes obtained 3-hexene to a dodecene mixture.

Process steps (b) and (c) are now closer explained.

Process stage (b) hydroformylation

In process step (b), the C ₂ to C ₂₉ alkene or its mixture required for the production of the desired saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture becomes the corresponding C ₃ to C ₃₀ alkane or its mixture Mixture hydroformylated by reaction with carbon monoxide and hydrogen. Depending on this, the 1-butene, cis-2-butene, trans-2-butene or its mixture, the C ₂ -C ₂₉ -alkene or its mixture from the optional process step (a) or a mixture of both is to be used for this ,

In the process according to the invention, the hydroformylation can generally be carried out in the manner which is customary and known to the person skilled in the art. A good overview with numerous further references can be found for example in M. Beller et al., Journal of Molecular Catalysis A, 104, 1995, pages 17 edition ^th to 85 or in Ullmann's Encyclopedia of Industrial Chemistry, 6, 2000 electronic release, Chapter " ALDEHYDES, ALIPHATIC AND ARALIPHATIC - Saturated Aldehydes ". The information given there enables the person skilled in the art to hydroformylate both the linear and the branched alkenes.

The hydroformylation is usually in the temperature range from 70 to 200 ° C and at a carbon monoxide / hydrogen pressure of 1 up to 35 MPa abs carried out in the presence of a catalyst. in the A carbon monoxide / hydrogen molar ratio is generally used from 0.1 to 10, preferably from 0.2 to 2. Since the Hydroformylation as a reaction product preferred to the alkanals and should not lead to alcohols, one chooses particularly preferred a carbon monoxide / hydrogen molar ratio 0.9 to 1.1.

The hydroformylation can be carried out with the addition of inert Solvents as well as without their addition. Suitable inert solvents are, for example, aliphatic and aromatic hydrocarbons (e.g. hexane, petroleum ether, toluene, Xylene).

Particularly suitable as catalytically active species are metal complexes of the general formula H _x M _y (CO) _z L _q , where M is a metal from the 8th to 10th group of the Periodic Table, L is a monodentate or multidentate ligand which is a phosphine , Phosphite, amine, pyridine or any other donor compound, also in polymeric form, and x, y, z and q are an integer, depending on the valence of the metal and the binding force of the ligand L, where q is also 0 can be. The catalytically active species is generally only formed during the actual reaction from a suitable metal precursor compound, the ligand L, carbon monoxide and hydrogen.

The metal M is preferably cobalt, Ruthenium, rhodium, platinum or iridium and in particular cobalt, Rhodium and ruthenium. As suitable Rhodium precursor compounds are rhodium (II) and rhodium (III) salts, such as Rhodium (III) chloride, rhodium (III) nitrate, rhodium (III) sulfate, Potassium rhodium sulfate, rhodium (II) carboxylate, Rhodium (III) carboxylate, rhodium (II) acetate, rhodium (III) acetate, rhodium (III) oxide and salts of rhodium (III) acid (e.g. Trisammonium hexachlororhodate (III)) and rhodium complexes, such as Rhodium biscarbonylacetylacetonat and Acetylacetonato-bisethylen-rhodium (I) called. Preferred rhodium precursors are preferred Rhodium biscarbonyl acetylacetonate and phodium acetate used. As suitable Cobalt precursor compounds are cobalt (II) chloride, Cobalt (II) sulfate, cobalt (II) carbonate, cobalt (II) nitrate, their Amine or hydrate complexes, cobalt carbocyclates (e.g. cobalt acetate, Cobalt (2-ethylhexanoate), cobalt naphthanoate or Cobalt caprolactomat) and the carbonyl complexes of cobalt, such as Dicobalt octacarbonyl, tetrakobalt dodecacarbonyl or Hexacobalthexadecacarbonyl called.

Examples of suitable ligands are triarylphosphines (e.g. triphenylphosphine), triphenylphosphites, triarylphosphonites, Phosphabenzenes, Trialkylphosphine and Phosphametallocene called. Also underivatized and derivatized as ligands Polymers, such as polyalkyleneimines, in particular polyethyleneimines; Polyvinylamines with aliphatic nitrogenous Residues on the polymer chain; Polymers of ethylenically unsaturated Carboxamides such as poly (meth) acrylamides; Polymers acyclic or cyclic N-vinylamides, such as polyvinylformamide or Polyvinyl caprolactam or polyvinyl polymers are suitable. they are described for example in WO 99/36382, whereupon explicitly Reference is made. Furthermore, are suitable ligands also phosphorus chelate compounds as in DE-Az. 101 15 689.8 described, called, with explicit reference to this application is taken.

The hydroformylation in step (b) is preferably carried out in the presence of a carbon monoxide / hydrogen mixture and a metal complex compound which is homogeneously dissolved in the reaction medium and comprises a metal from the 8th to the 10th group of the periodic table and a polyethyleneimine, which units of the general formula (I) or branched isomers thereof


in which the sum of m + n is at least 10 and R each independently of one another is hydrogen, alkyl, cycloalkyl, aryl, aralkyl, acyl radicals having up to 30 carbon atoms or hydroxyalkyl (poly) oxyalkylene radicals having up to 500 Alkyleneoxy units mean, by. Suitable polyethyleneimines are described, for example, in WO 99/36382, to which reference is explicitly made.

The preferably used polyethyleneimines (I) have a molar mass of more than 1000 g / mol and preferably more than 10000 up to 10 ⁶ g / mol.

As preferred alkyl, cycloalkyl, aryl, aralkyl and acyl radicals are the unbranched or branched, optionally substituted C ₁ -C ₂₀ -alkyl, C ₅ -C ₁₆ -cycloalkyl, C ₆ -C ₁₀ aryl, C ₇ to C ₁₀ aralkyl and C ₂ to C ₂₁ acyl radicals, such as, for example, methyl, ethyl, 1-propyl, 2-propyl (sec. Propyl), 1-butyl, 2 -Butyl (sec.Butyl), 2-methyl-1-propyl (iso-butyl), 2-methyl-2-propyl (tert-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 3-methyl -2-butyl, 2-methyl-2-butyl, 1-hexyl, 1-heptyl, 1-octyl, 2-ethyl-1-hexyl, 1-nonyl, 1-decyl, 1-dodecyl, 1-tetradecyl, 1 -Hexadecyl, 1-octadecyl, 1-icosyl, cyclopentyl, cyclohexyl, cyclooctyl, phenyl, 2-methylphenyl (2-tolyl), 3-methylphenyl (3-tolyl), 4-methylphenyl (4-tolyl), 2,4- Dimethylphenyl, 2, 6-dimethylphenyl, 2,4,6-trimethylphenyl, 1-naphthyl, 2-naphthyl and phenylmethyl (benzyl).

The preferred alkyleneoxy units are the C ₂ -C ₆ -alkyleneoxy units, such as, for example, ethyleneoxy, propyleneoxy, butyleneoxy, pentyleneoxy and hexyleneoxy.

Polyethyleneimines (I) or branched isomers thereof are particularly preferably used, in which the radicals R each independently of one another denote hydrogen and identical or different acyl radicals having up to 30 carbon atoms. The particularly preferred polyethyleneimines (I) have the following structural elements (Ia) or branched isomers thereof


in which R 'independently of one another denotes alkyl having 1 to 29 carbon atoms.

The preferred alkyl radicals for R 'are the unbranched or branched, optionally substituted C ₁ -C ₂₁ -alkyl radicals, such as, for example, methyl, ethyl, 1-propyl, 2-propyl (sec. Propyl), 1-butyl, 2-butyl (sec.butyl), 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl (tert-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 1- Hexyl, 1-heptyl, 2-heptyl, 3-heptyl, 1-octyl, 2,4,4-trimethylpentyl, 1-nonyl, 2-methyl-2-octyl, 1-decyl, 1-undecyl, 1-dodecyl, 1-Tridecyl, 1-tetradecyl, 1-pentadecyl, 1-hexadecyl, 1-heptadecyl, 1-octadecyl, 1-nonadecyl, 1-icosyl and 1-henicosyl.

Other polyethyleneimines (I) used with particular preference have units of the formula (Ib) or branched isomers thereof as characteristic structural elements


in which R "is hydrogen or C ₁ - to C ₄ -alkyl and o can have a value of 0 and 500. These compounds are referred to as alkoxylated polyethyleneimines and are described, for example, in US Pat. No. 5,846,453 and US Pat. No. 3,907,701 Preliminary literature, in particular with regard to the production of the polyamines, is expressly referred to and the details thereof are to be considered part of the present application.

The structures shown in formulas (I), (Ia) and (Ib) above are idealized formulas for the case where the polyethyleneimines shown are linear. The repetition units can be in any order, for example statistical, in sequence. The polyethyleneimine polymers to be used in the catalyst system according to the invention can also be partially branched and have, for example, structural elements of the type shown below:

If present in connection with polyethyleneimines from "branched isomers" is mentioned, so are Constitutional isomers addressed that differ from the structure shown single or multiple insertion of one of the formulas (I), (Ia) and (Ib) repeat units shown in parentheses between an NH bond. You are about tertiary Nitrogen atoms branched.

Polyethyleneimines are generally obtained by homo- or copolymerization of the aziridine, optionally with other monomers, such as vinylamides, vinylamines, acrylamides, acrylamines, acrylic esters, methacrylic esters and olefins, such as ethene, propene, butene or butadiene, with an average molecular weight of 200 to 2.10 ⁶ g / mol produced.

The particularly preferred acylated polyethyleneimines (Ia) are generally obtained by reacting the polyethyleneimines with carboxylic acids, such as, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, lauric acid, 2-ethylhexanoic acid, or natural C ₁₈ fatty acids, the degree of amidation being 1 to close 100%, preferably 30 to close to 100%, based on the amidatable amino groups. Details of the production can be found in the published patent application DE-A 37 27 704. The particularly preferred polyoxyalkylated polyethyleneimines (Ib) are generally prepared by reacting the polyethyleneimines with up to 500 mol ethylene oxide, propylene oxide or butylene oxide per monomer unit of the polyethyleneimine. Details of the production can be found in US Pat. No. 5,846,453.

Based on the total mass of the reaction batch at Hydroformylation is the proportion of polyethyleneimine (I) in the Generally 0.5 to 15, preferably 1 to 10 and particularly preferably 3 up to 7.5% by weight.

The particular advantage of using the ones described above Polyethyleneimine lies in its distinctive property, the Stabilize hydroformylation catalysts and thus a high To ensure activity and a long service life.

Furthermore, the hydroformylation in step (b) is preferably carried out in the presence of a carbon monoxide / hydrogen mixture and a metal complex compound which is homogeneously dissolved in the reaction medium and comprises a metal from the 8th to 10th group of the periodic table and a phosphorus chelate compound of the general formula (II)


in the
Q is a bridge group of the formula


is what
A ¹ and A ² independently represent O, S. SiR ^a R ^b , NRC or CR ^d R ^e , where
R ^a , R ^b and R ^c independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,
R ^d and R ^e independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group R ^d together with another group R ^d or the group R ^e together with another group R ^{e form} an intramolecular bridge group D,
D is a double-bonded bridge group selected from the groups


is where
R ⁹ and R ¹⁰ independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are connected to one another to form a C ₃ -C ₄ -alkylene bridge,
R ¹¹ to R ¹⁴ independently of one another for hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, SO ₃ H, sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² E ³⁺ X ^- , Acyl or nitro,
c is 0 or 1,
Y represents a chemical bond,
R ⁵ to R ⁸ independently of one another are hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, COOR ^f , COO ^- M ⁺ , SO ₃ R ^f , SO ^- ₃ M ⁺ , NE ¹ E ² , NE ¹ E ² E ^{3 +} X ^- , alkylene- NE ¹ E ² E ³⁺ X ^- , OR ^f , SR ^f , (CHR ^g CH ₂ O) _x R ^f , (CH ₂ N (E ¹ )) _x R ^f , (CH ₂ CH ₂ N (E ¹ )) _x R ^f , halogen, trifluoromethyl, nitro, acyl or cyano,
wherein
R ^f , E ¹ , E ² and E ³ each represent the same or different radicals selected from hydrogen, alkyl, cycloalkyl or aryl,
R ^{g represents} hydrogen, methyl or ethyl,
M ^{+ stands} for a cation,
X ^{- represents} an anion, and
x represents an integer from 1 to 120,
or
R ⁷ and / or R ⁸ together with two adjacent carbon atoms of the benzene nucleus to which they are attached represent a condensed ring system with 1, 2 or 3 further rings,
a and b independently of one another denote the number 0 or 1 and
R ¹ to R ⁴ independently of one another are hetaryl, hetaryloxy, alkyl, alkoxy, aryl, aryloxy, cycloalkyl, cycloalkoxy, heterocycloalkyl, heterocycloalkoxy or an NE ¹ E ² group, with the proviso that R ¹ and R ^{3 are} via the nitrogen atom are pyrrole groups bonded to the phosphorus atom P or wherein R ¹ together with R ² and / or R ³ together with R ^{4 is} a double-bonded group E of the formula Py-IW containing at least one pyrrole group bonded to the phosphorus atom P via the pyrrolic nitrogen atom, wherein
Py is a pyrrole group
I stands for a chemical bond or for O, S, SiR ^a R ^b , NR ^c or CR ^h R ⁱ ,
W represents cycloalkyl, cycloalkoxy, aryl, aryloxy, hetaryl or hetaryloxy, and
R ^h and R ⁱ independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,
or a bispyrrole group of the formula Py-I-Py bonded to the phosphorus atom P via the nitrogen atoms
forms, by.

For the purpose of explaining the preferred phosphorus chelate compound (II), the term "alkyl" includes straight-chain and branched alkyl groups. These are preferably straight-chain or branched C ₁ -C ₁₂ alkyl, preferably C ₁ -C ₈ alkyl and particularly preferably C ₁ -C ₄ alkyl groups. Examples of alkyl groups are in particular methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl, 1,2 -Dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl , 2,3-dimethylbutyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethylbutyl, 2-ethylbutyl, 1 -Ethyl- 2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, n-octyl, 2-ethylhexyl, 2-propylheptyl. The term "alkyl" also includes substituted alkyl groups which generally have 1, 2, 3, 4 or 5, preferably 1, 2 or 3 and particularly preferably 1, substituents selected from the groups cycloalkyl, aryl, hetaryl, halogen, NE ¹ E ² , NE ¹ E ² E ³⁺ , carboxyl, carboxylate, -SO ₃ H and sulfonate.

The term "alkylene" stands for straight-chain or branched Alkanediyl groups with 1 to 4 carbon atoms.

The term “cycloalkyl” encompasses unsubstituted and substituted cycloalkyl groups, preferably C ₅ to C ₇ cycloalkyl groups, such as cyclopentyl, cyclohexyl or cycloheptyl, which, in the case of a substitution, generally 1, 2, 3, 4 or 5, preferably 1, 2 or 3 and particularly preferably 1 substituent selected from the groups alkyl, alkoxy and halogen.

The term "heterocycloalkyl" encompasses saturated, cycloaliphatic groups with generally 4 to 7, preferably 5 or 6 ring atoms, in which 1 or 2 of the ring carbon atoms are replaced by heteroatoms selected from the elements oxygen, nitrogen and sulfur and which are optionally substituted can, in the case of a substitution, these heterocycloaliphatic groups 1, 2 or 3, preferably 1 or 2, particularly preferably 1 substituents selected from alkyl, aryl, COOR ^f , COO ^- M ⁺ and NE ¹ E ² , preferably alkyl can. Examples of such heterocycloaliphatic groups are pyrrolidinyl, piperidinyl, 2,2,6,6-tetramethyl-piperidinyl, imidazolidinyl, pyrazolidinyl, oxazolidinyl, morpholidinyl, thiazolidinyl, isothiazolidinyl, isoxazolidinyl, piperazinyl-, tetrahydrothiophenyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, tetrahydroflanyl, and tetrahydroflanyl, called tetrahydroflanyl, tetrahydroflanyl, and tetrahydrothiophenyl, tetrahydroflanyl.

The term "aryl" encompasses unsubstituted as well as substituted aryl groups, and preferably stands for phenyl, tolyl, xylyl, mesityl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl or naphthacenyl, particularly preferably for phenyl or naphthyl, these aryl groups generally being substituted 1, 2, 3, 4 or 5, preferably 1, 2 or 3 and particularly preferably 1 substituent, selected from the groups alkyl, alkoxy, carboxyl, carboxylate, trifluoromethyl, -SO ₃ H, sulfonate, NE ¹ E ² , alkylene NE ¹ E ² , nitro, cyano or halogen.

The term "hetaryl" encompasses unsubstituted or substituted heterocycloaromatic groups, preferably the groups pyridyl, quinolinyl, acridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, and the subgroup of the "pyrrole group", these heterocycloaromatic groups generally being substituted by 1, 2 or 3 substituents selected from the groups alkyl, alkoxy, carboxyl, carboxylate, -SO ₃ H, sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² , trifluoromethyl or halogen.

The term "pyrrole group" stands for a series of unsubstituted or substituted, heterocycloaromatic groups which are structurally derived from the pyrrole backbone and contain a pyrrolic nitrogen atom in the heterocycle which can be covalently linked to other atoms, for example the phosphorus atom P. The term "pyrrole group" thus includes the unsubstituted or substituted groups pyrrolyl, imidazolyl, pyrazolyl, indolyl, purinyl, indazolyl, benzotriazolyl, 1,2,3-triazolyl, 1,3,4-triazolyl and carbazolyl, which in the case of a substitution in general 1, 2 or 3, preferably 1 or 2, particularly preferably 1 substituent selected from the groups alkyl, alkoxy, acyl, carboxyl, carboxylate, -SO ₃ H, sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² , Trifluoromethyl or halogen, can wear.

Accordingly, the term "bispyrrole group" includes divalent groups of the formula

PY-I-PY,

which contain two pyrrole groups linked by direct chemical bonding or alkylene, oxa, thio, imino, silyl or alkylimino groups, such as the bisindoldiyl group of the formula


as an example of a bispyrrole group which contains two directly linked pyrrole groups, in this case indolyl, or the bispyrroldiylmethane group of the formula


as an example of a bispyrrole group which contains two pyrrole groups linked via a methylene group, in this case pyrrolyl. Like the pyrrole groups, the bispyrrole groups can also be unsubstituted or substituted and, in the case of a substitution per pyrrole group unit, generally 1, 2 or 3, preferably 1 or 2, in particular 1, substituents selected from alkyl, alkoxy, carboxyl, carboxylate, -SO ₃ H, Sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² , trifluoromethyl or halogen, wear, with this information on the number of possible substituents, the linkage of the pyrrole group units by direct chemical bond or by the linkage mediated by the above groups is not considered a substitution becomes.

In the context of this invention, carboxylate and sulfonate preferably represent a derivative of a carboxylic acid function or a sulfonic acid function, in particular a metal carboxylate or sulfonate, a carboxylic acid or sulfonic acid ester function or a carboxylic acid or sulfonic acid amide function. These include e.g. B. the esters with C ₁ -C ₄ alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol and tert-butanol.

The above explanations for the terms "alkyl", "cycloalkyl", "Aryl", "Heterocycloalky" and "Hetaryl" apply accordingly to the terms "alkoxy", "cycloalkoxy", "aryloxy", "Heterocycloalkoxy" and "Hetaryloxy".

The term "acyl" stands for alkanoyl or aroyl groups with im generally 2 to 11, preferably 2 to 8 carbon atoms, for example for acetyl, propionyl, butyryl, pentanoyl, Hexanoyl, heptanoyl, 2-ethylhexanoyl, 2-propylheptanoyl, Benzoyl or naphthoyl group.

The group NE ¹ E ² preferably represents N, N-dimethyl, N, N-diethyl, N, N-dipropyl, N, N-diisopropyl, N, N-di-n-butyl, N, N-di-t . -butyl, N, N-dicyclohexyl or N, N-diphenyl.

Halogen stands for fluorine, chlorine, bromine and iodine, preferably for Fluorine, chlorine and bromine.

The cation M ⁺ serves only as a counterion for the neutralization of negatively charged substituent groups, such as the COO ^- or the sulfonate group, and can in principle be chosen as desired. Alkali metal, in particular Na ⁺ , K ⁺ , Li ⁺ ions or onium ions, such as ammonium, mono-, di-, tri-, tetra-alkyl-ammonium, phosphonium, tetra-alkyl, are therefore preferred -phosphonium or tetra-aryl-phosphonium ions are used.

The same applies to the anion X ^- , which serves only as a counterion of positively charged substituent groups, such as the ammonium groups, and can be chosen as desired, with halide ions X ^{- being} preferred in general, in particular chloride and bromide.

Y represents a chemical bond, i.e. the point of attachment of the bridge group Q to the groups -O- or, if a and / or b is 0, to the groups PNR ¹ R ² or PNR ³ R ⁴ .

In the bridging group Q, the groups A ¹ and A ^{2 can} in general independently of one another represent O, S, SiR ^a R ^b , NR ^c or CR ^d R ^e , the substituents R ^a , R ^b and R ^C generally being independent of one another can be hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, whereas the groups R ^d and R ^e independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group R ^d together with a further group R ^d or the group R ^e together with another group R ^e can form an intramolecular bridge group D.

D is a double-bonded bridge group that is generally selected from the groups


in which R ⁹ and R ¹⁰ independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are linked together to form a C ₃ - to C ₄ -alkylene group and R ¹¹ , R ¹² , R ¹³ and R ¹⁴ independently of one another for hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, SO ₃ H, sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² E ³⁺ X ^- , Aryl or nitro can stand. The groups R ⁹ and R ¹⁰ are preferably hydrogen, C ₁ - to C ₁₀ -alkyl or carboxylate and the groups R ¹¹ , R ¹² , R ¹³ and R ^{14 are} hydrogen, C ₁ - to C ₁₀ -alkyl, halogen, in particular fluorine, chlorine or bromine, trifluoromethyl, C ₁ - to C ₄ -alkoxy, carboxylate, sulfonate or C ₁ - to C ₈ -aryl. R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are particularly preferably hydrogen. For use in an aqueous reaction medium, preference is given to those phosphorus chelate compounds in which 1, 2 or 3, preferably 1 or 2, in particular 1 of the groups R ¹¹ , R ¹² , R ¹³ and / or R ¹⁴ for a COO ^- Me ⁺ -, are a SO ₃ ^- M ⁺ - or a NE ¹ E ² E ³⁺ X ^- group, where M ⁺ and X ^{- have} the meaning given above.

Particularly preferred bridge groups D are the ethylene group


and the 1,2-phenylene group

If R ^d forms an intramolecular bridging group D with another group R ^d or R ^e with another group R ^e , ie the index c in this case is 1, it is inevitable that both A ¹ and A ^{2 are} CR ^d R ^e group and the bridge group Q in this case has a triptycene-like carbon skeleton.

In addition to those with a triptycene-like carbon skeleton, preferred bridging groups Q are those in which the index c is 0 and the groups A ¹ and A ^{2 are} selected from the groups O, S and CR ^d R ^e , in particular under O, S, Methylene group (R ^d = R ^e = H), the dimethylmethylene group (R ^d = R ^e = CH ₃ ), the di-n-propylmethylene group (R ^d = R ^e = n-propyl) or the di-n-butylmethylene group (R ^d = R ^e = n-butyl). In particular, those bridge groups Q are preferred in which A ¹ is different from A ² , where A ^{1 is} preferably a CR ^d R ^e group and A ^{2 is} preferably an O or S group, particularly preferably an oxa group O.

Particularly preferred bridging groups Q are thus those which consist of a triptycene like or xanthene type (A ^1: CR ^d R ^e, A ^2: O) backbone are constructed.

The substituents R ⁵ , R ⁶ , R ⁷ and R ⁸ generally represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl and hetaryl. R ⁵ and R ⁷ are preferably hydrogen and R ⁶ and R ^{8 are} C ₁ - to C ₄ -alkyl, such as, for. B. methyl, ethyl, n-propyl, n-butyl or tert-butyl. It goes without saying that the positions of the phenyl rings of the bridging group Q which are not occupied by substituents bear a hydrogen atom.

Since the substituents R ⁵ , R ⁶ , R ⁷ and R ⁸ generally make practically no contribution to the catalytic activity of the catalysts prepared from the phosphorus chelate ligands according to the invention, apart from an influence on the solubility, R ⁵ , R ⁶ , R ⁷ and R ^{8 is} preferred for hydrogen.

If R ⁵ and / or R ⁷ stand for a fused-on, ie fused, ring system, then it is preferably benzene or naphthalene rings. Fused benzene rings are preferably unsubstituted or have 1, 2 or 3, in particular 1 or 2, substituents which are selected from alkyl, alkoxy, halogen, SO ₃ H, sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² , trifluoromethyl, Nitro, COOR ^f , alkoxycarbonyl, acyl and cyano. Fused naphthalene rings are preferably unsubstituted or have a total of 1, 2 or 3, in particular 1 or 2, of the substituents mentioned above for the fused benzene rings in the non-fused ring and / or in the fused ring.

If the use of the phosphorus chelate compounds in an aqueous hydroformylation medium is intended, at least one of the radicals R ⁵ , R ⁶ , R ⁷ and / or R ^{8 represents} a polar (hydrophilic) group, in which case, as a rule, the complex formation with a metal of the 8th to group 10 of the periodic table water-soluble phosphorus chelate complexes result. The polar groups are preferably selected from COOR ^f , COO ^- M ⁺ , SO ₃ R ^f , SO ₃ ^- M ⁺ , NE ¹ E ² , alkylene-NE ¹ E ² , NE ¹ E ² E ³⁺ X ^- , alkylene- NE ¹ E ² E ³⁺ X ^- , OR ^f , SR ^f , (CHR ^g CH ₂ O) _x R ^f or (CH ₂ CH ₂ N (E ¹ )) _x R ^f , where R ^f , E ¹ , E ² , E ³ , R ^g , M ⁺ , X ^- and x have the meanings given above.

The bridging group Q is connected via the chemical bond Y either directly or via an oxa group O to the groups PnR ¹ R ² or PnR ³ R ⁴ .

The individual phosphorus P of the phosphorus chelate compounds are each connected via two covalent bonds with two substituents R ¹ and R ² or R ³ and R ⁴ , the substituents R ¹ , R ² , R ³ and R ^{4 being} independently of one another for hetaryl, hetaryloxy, Alkyl, alkoxy, aryl, aryloxy, cycloalkyl, cycloalkoxy, heterocycloalkyl, heterocycloalkoxy or an NE ¹ E ² group, with the proviso that R ¹ and R ^{3 are} pyrrole groups bonded to the phosphorus atom P via the pyrrolic nitrogen atom. The substituents R ² and / or R ⁴ are also advantageously pyrrole groups bonded to the phosphorus atom P via the pyrrolic nitrogen atom. Furthermore, the substituent R ¹ together with the substituent R ² or the substituent R ³ together with the substituent R ⁴ or the substituent R ¹ together with the substituent R ² and the substituent R ³ together with the substituent R ^{4 can be} via the pyrrolic Form nitrogen atoms bonded to the phosphorus atom P bispyrrole group.

The meaning of each mentioned in the previous paragraph Expressions correspond to the definition given at the beginning.

In a further advantageous embodiment, the substituent R ¹ together with the substituent R ² or the substituent R ³ together with the substituent R ⁴ or the substituent R ¹ together with the substituent R ² and the substituent R ³ together with the substituent R ⁴ Bivalent group of the formula containing pyrrole group bonded to the phosphorus atom P via the pyrrolic nitrogen atom

Py-IW

form where Py is a pyrrole group, I stands for a chemical bond or for O, S, SiR ^a R ^b , NR ^c or CR ^h R ⁱ , W stands for cycloalkyl, cycloalkoxy, aryl, aryloxy, hetaryl or hetaryloxy and R ^h and R ⁱ independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, the terms used here having the meaning explained above.

In the process according to the invention, a compound of the general formulas (IIa), (IIb) or (IIc) is preferably used as the phosphorchelate compound (II) in the hydroformylation




on.

The particular advantage of using the ones described above Phosphorus chelate ligands (I) in the hydroformylation lie in its extremely high selectivity for the formation of terminal Alkanals. Even when using alkenes with internal Double bonds are predominantly terminal alkanals, the Selectivity to terminal alkanals is sometimes even clear is over 90%.

Depending on the requirements in the subsequent stages, it is possible and optionally advantageous, that obtained in process step (b) Alkanal mixture in the desired fractions, for example to separate by distillation.

Process stage (c)

oxidation

In process step (c), the C ₃ to C ₃₀ alkanal or its mixture obtained from process step (b) is oxidized to the saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture. In the process according to the invention, the oxidation can generally be carried out in the manner which is customary and known to the person skilled in the art. A good overview with numerous further references is found for example in Ullmann's Encyclopedia of Industrial Chemistry, 6 ^th edition, 2000 electronic release, Chapter "CARBOXYLIC ACIDS, Aliphatic - Production". The information provided there enables the person skilled in the art to oxidize the C ₃ to C ₃₀ alkanal obtained from process step (b) into the corresponding carboxylic acids.

The oxidation is usually carried out with an oxygen containing gas in the presence or absence of a catalyst or in the presence or absence of one Inhibitor. As a rule, the oxidation takes place in the liquid phase.

The oxidizing agent to be used contains after Molecular oxygen or oxygen-containing processes according to the invention Gas mixtures. The oxygen content in the gas containing oxygen is generally 5 to 100 vol .-%. At 100 vol% the remaining part is usually so-called Inert gases, which compared to the educts and products under the existing conditions inert or at least largely inert are. Examples of suitable inert gases are nitrogen, Noble gases, carbon dioxide and water vapor called. Preferably sets one as air containing oxygen, which as needed enriched with additional oxygen or with additional inert gas, preferably nitrogen, can be depleted. Especially air is preferably used in the oxidation.

The oxidation is generally carried out at a temperature of 20 to 150 ° C and preferably from 20 to 100 ° C through. The pressure is generally 0.05 to 3 MPa abs and preferably 0.1 to 2 MPa abs.

In principle, all reaction apparatuses can be used as reaction apparatuses are used, which are suitable for gas-liquid reactions are. Examples are bubble columns, jet loop reactors and stirred kettle (preferably with corresponding Fumigation devices) called.

The oxidation can take place both with the addition of inert solvents as well as without their addition. Suitable inert Examples of solvents are ketones such as acetone and esters such as ethyl acetate, nitro hydrocarbons such as Nitrobenzene or hydrocarbons such as alkanes (e.g. heptane) and aromatics (e.g. toluene). If solvents are used, so their content is generally less than 50% by weight of the entire reaction mixture. The oxidation is preferably carried out without Use of solvents.

If catalysts are used in the oxidation, include these usually salts of redox-capable metals such as for example of silver, cerium, cobalt, chrome, copper, iron, Manganese, molybdenum, nickel or vanadium. Usually this is Amount of catalyst about 0.05 to 5 wt .-% based on the entire reaction mixture.

If catalysts are used in the oxidation, then this is the case are generally alkali metal and alkaline earth metal salts. Inhibitors primarily suppress unwanted ones Side reactions. Basic salts of sodium and Potassium, such as the hydroxides, oxides, acetates, Carbonates and the salts of the corresponding carboxylic acids. Especially sodium hydroxide and potassium hydroxide are preferred. The reaction can, for example, with an alkali metal hydroxide as an inhibitor be started and by returning the resulting Alkali metal carboxylate of the corresponding carboxylic acid upright be preserved. Usually the amount of inhibitor is about 0.1 to 10 wt .-% and preferably 0.2 to 2.5 wt .-% based on the entire reaction mixture.

The one for the specific oxidation process to be carried out conditions to be set and catalysts to be used or inhibitors and their amounts can be in the specialist the usual way.

Depending on the requirements of the desired carboxylic acids, it is possible and possibly advantageous, that in the process stage (c) carboxylic acid mixture obtained in the desired fractions, for example, to separate by distillation.

• a) durch Metathese und/oder Oligomerisation in ein C₂- bis C₂₉-Alken oder dessen Gemisch überführt;
• b) das C₂- bis C₂₉-Alken oder dessen Gemisch aus der Verfahrensstufe (a) durch Hydroformylierung in ein C₃- bis C₃₀-Alkanal oder dessen Gemisch überführt; und
• c) das C₃- bis C₃₀-Alkanal oder dessen Gemisch aus der Verfahrensstufe (b) durch Oxidation in die gesättigte aliphatische C₃- bis C₃₀-Carbonsäure oder deren Gemisch überführt.

Preferred in the process according to the invention is a process in which 1-butene, cis-2-butene, trans-2-butene or a mixture thereof is used,

• a) converted into a C ₂ -C ₂₉ alkene or a mixture thereof by metathesis and / or oligomerization;
• b) the C ₂ -C ₂₉ alkene or its mixture from process step (a) is converted by hydroformylation into a C ₃ -C ₃₀ alkanal or its mixture; and
• c) the C ₃ to C ₃₀ alkanal or its mixture from process step (b) is converted by oxidation into the saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture.

This is also the preferred method of course, that between the individual implementation stages Steps, such as various processing and cleaning steps as well as the isolation of certain mixtures or pure components can be carried out.

• a) durch Metathese in ein C₂- bis C₆-Alken oder dessen Gemisch überführt; und
• b) das C₂- bis C₆-Alken oder dessen Gemisch durch Dimerisierung und/oder Trimerisierung in ein C₄- bis C₁₈-Alken oder dessen Gemisch überführt.

Particularly preferred in the process according to the invention is a process in which 1-butene, cis-2-butene, trans-2-butene or a mixture thereof in step (a)

• a) converted by metathesis into a C ₂ -C ₆ alkene or a mixture thereof; and
• b) the C ₂ to C ₆ alkene or its mixture is converted into a C ₄ to C ₁₈ alkene or its mixture by dimerization and / or trimerization.

This particularly preferred process is particularly suitable for producing C ₅ to C ₁₉ carboxylic acids from the feedstock containing butenes mentioned. In particular, this makes it possible to obtain a C ₅ alkene-rich and a C ₆ alkene-rich stream in step (i), this to a C ₁₀ alkene-rich and a C ₁₂ alkene in step (ii) to implement a rich stream and to obtain saturated aliphatic C ₁₁ carboxylic acids or saturated aliphatic C ₁₃ carboxylic acids or mixtures thereof by the subsequent hydroformylation and oxidation.

The process according to the invention enables the production of saturated aliphatic C ₃ to C ₃₀ carboxylic acids or mixtures thereof. Pentanoic acid (valeric acid), 2-methylbutyric acid, n-heptanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-propylheptanoic acid, n-tridecanoic acid, iso-tridecanoic acid, neo-tridecanoic acid, 2-methyldodecenoic acid or mixtures thereof are preferably produced by the process according to the invention ,

In a preferred embodiment, raffinate II is hydroformylated in process step (b) and, after the hydroformylation catalyst has been separated off in process step (c), the mixture obtained is oxidized to a mixture of C ₅ -carboxylic acids which contains, in particular, n-pentanoic acid (n-valeric acid).

In another preferred embodiment, raffinate II is metathesized according to process step (a) and, in particular, a C ₅ alkene mixture and a C ₆ alkene mixture are isolated from the reaction mixture obtained. The C ₅ alkene mixture can now be hydroformylated in process step (b) and oxidized in process step (c) to a mixture of C ₆ carboxylic acids, which contains in particular n-hexanoic acid, 2-methylpentanoic acid and 2-ethylbutyric acid. The C ₆ -alkene mixture can now be hydroformylated in process step (b) and oxidized in process step (c) to a mixture of C ₇ carboxylic acids, which contains in particular n-heptanoic acid, 2-methylhexanoic acid and 2-ethylpentanoic acid.

In another preferred embodiment, raffinate II is metathesized according to process step (a) and, in particular, a C ₅ alkene mixture and a C ₆ alkene mixture are isolated from the reaction mixture obtained. The C ₅ alkene mixture can be dimerized according to process step (a) to a C ₁₀ alkene mixture, hydroformylated according to process step (b) and according to process step (c) to a mixture of C ₁₁ carboxylic acids, which is in particular iso -Undecanoic acid, neo-undecanoic acid, n-undecanoic acid and 2-methyldecanoic acid are oxidized. The C ₆ alkene mixture can be dimerized according to process step (a) to a C ₁₂ alkene mixture, hydroformylated according to process step (b) and according to process step (c) to a mixture of C ₁₃ carboxylic acids, which is in particular iso- Contains tridecanoic acid, neo-tridecanoic acid, n-tridecanoic acid and 2-methyldodecanoic acid.

The process according to the invention enables the production of saturated aliphatic C ₃ to C ₃₀ carboxylic acids, which is based on an easily accessible and economically attractive raw material base, in particular when using the readily available C ₄ streams from steam and FCC crackers, in a simple manner and cost-effective design of the entire system enables (low investment costs), is technically simple and safe to carry out in its entirety and enables a high yield and high space-time yield of the desired carboxylic acids. The individual process stages can be carried out without the use of drastic and complex process conditions and enable a high yield of the desired valuable products in each stage. Furthermore, the process according to the invention is flexible with regard to the composition of the starting material containing butenes and, owing to the controllability within the individual process steps, also offers a high degree of flexibility with regard to the composition of the carboxylic acids.

The invention furthermore relates to the use of the saturated aliphatic C ₃ - to C ₃₀ -carboxylic acids produced according to the invention or their mixtures for the production of dyes, pharmaceutical and agricultural active ingredients, plastics and surfactants.

Examples Synthesis of amidated polyethyleneimine

In a 2 L four-necked flask with stirrer, dropping funnel and one Distillation bridge were under 297 g (1.48 mol) of lauric acid melted in a gentle stream of nitrogen at 100 ° C. Then at 150 ° C over the dropping funnel 212.5 g 50 wt .-% solution of a polyethyleneimine (2.47 mol) of a added average molecular weight of 460000. The The dropping rate was chosen so that the temperature could be kept between 150 and 155 ° C and the supplied Water distilled off. The mixture was then at 180 ° C for 15 hours heated, the water of reaction of the amidation being distilled off has been. The melt was cooled to 100 ° C, the reactor removed and crushed at room temperature. 364 g of one yellow solid obtained.

Synthesis of phosphorus chelate ligand A

5 g (13.3 mmol) of 1,8-dibromo-3,6-di-tert-butylxanthene were placed under argon in tetrahydrofuran. At -50 ° C (223 K), 12.3 mL (30.7 mmol) of a 2.5 molar n-butyllithium in hexane solution were added. The reaction mixture was stirred for 2 hours, a colorless suspension being formed. 100 ml (100 mmol) of a 1 molar solution of hydrogen boron (BH ₃ ) in tetrahydrofuran were added dropwise at 0 ° C. and the mixture was stirred at 5 to 15 ° C. overnight. The mixture was then carefully hydrolyzed at 0 ° C. with 25 ml of water. 3 N potassium hydroxide solution (from 7.4 g KOH in 32 g water) and 10.4 g 30% H ₂ O ₂ solution were carefully added to the reaction mixture and the mixture was heated under reflux for 2 hours. After cooling to room temperature, the mixture was neutralized with 18% hydrochloric acid. After phase separation, the organic phase was washed twice with sodium chloride solution and dried over sodium sulfate and evaporated to dryness. 1,8-dihydroxy-3,6-di-tert-butylxanthene was obtained in 4.7 g yield (100% of theory).

5.2 g (38 mmol) of phosphorus trichloride and 5.1 g (76 mmol) of pyrrole were placed under argon in tetrahydrofuran at -65 ° C (208 K). Then 1.5 g (114 mmol) of triethylamine were slowly added and the mixture was stirred at room temperature for 48 hours. 4.7 g (13.3 mmol) of 1,8-dihydroxy-3,6-di-tert-butylxanthene in 50 ml of tetrahydrofuran were added to this at room temperature, the temperature rising to 30 ° C. After stirring overnight, the resulting solid was filtered off under reduced pressure, the precipitate was washed with tetrahydrofuran and the combined organic phases were concentrated, giving a brown oil. The oil was recrystallized three times from hexane. The phosphorus chelate ligand A was obtained in 1.1 g yield (12% of theory).

example 1 Production of 2-pentene and 3-hexene by metathesis of a feed stream containing butenes

A practically butadiene-free C ₄ fraction (raffinate II) with a total butene content of 84.2% by weight and a ratio of 1-butene to 2-butenes of 1 to 1.06 was at 40 ° C. and 1 MPa abs in one Tubed reactor passed over a Re ₂ O ₇ / Al ₂ O ₃ catalyst with a Re ₂ O ₇ content of 10 wt .-%. The catalyst load was 4500 kg of C ₄ fraction per m ^{3 of} catalyst bed and hour. According to gas chromatographic analysis, the reactor discharge contained a mixture of C ₂ to C ₆ alkenes with the following composition:
1.15% by weight of ethene, 18.9% by weight of propene, 15.8% by weight of butanes, 13.3% by weight of 1-butene, 19.7% by weight of 2-butenes, 1 , 00% by weight of isobutene, 19.4% by weight of 2-pentene, 0.45% by weight of methylbutenes and 10.3% by weight of 3-hexene. From this, 2-pentene and 3-hexene, each with a purity of> 99% by weight, were separated off by distillation.

Example 2 Preparation of a mixture containing heptanoic acids Example 2A Hydroformylation of 3-hexene

In a 2.5 L autoclave, 500 g of 3-hexene from Example 1, 500 g of toluene, 31.3 mg of Rh (CO) ₂ (acac), where acac stands for acetylacetonate (source: Strem), and 2.77 g Polyethyleneimine, in which 60% of the amine groups were amidated with lauric acid and which was prepared in accordance with the "synthesis of amidated polyethyleneimine" described above. At room temperature, carbon monoxide and hydrogen were then introduced in a molar ratio of 1: 1 to a pressure of 18 MPa abs. The mixture was heated to 130 ° C., pressurized to 28 MPa abs with further carbon monoxide and hydrogen (molar ratio of 1: 1) and left under the conditions for 5 hours while maintaining the pressure and temperature. The autoclave was then cooled, decompressed and 1165 g of reaction mixture isolated. Toluene was separated off from the reaction mixture obtained by distillation and the discharge was analyzed by gas chromatography. This contained 22.8% by weight of n-heptanal, 41.3% by weight of 2-methylhexanal and 31.6% by weight of 2-ethylpentanal. The conversion of 3-hexene was 99%.

Example 2B Oxidation of the heptanal-containing mixture from Example 2A

Containing 63.2 g of the heptanal obtained from Example 2A The mixture was made up to 150 g with heptane, with potassium hydroxide to a calculated content of 0.5 wt .-% potassium heptanoate added and filled into a bubble column. Then was over a period of 20 hours at room temperature and Atmospheric pressure 20 NL / h air gas. The discharge contained gas chromatographic analysis 91% by weight of heptanoic acids (n-heptanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid). Sales of heptanal was 93%.

Example 3 Production of a predominantly n-heptanoic acid containing mixture Example 3A Hydroformylation of 3-hexene

0.4 mg Rh (CO) ₂ (acac) (source: Strem), where acac stands for acetylacetonate, and 10.5 mg phosphorus chelate ligand A, which was prepared in accordance with the "Synthesis of phosphorus chelate ligand A" described above, were obtained in 1 mL toluene dissolved and preformed for 30 minutes at 100 ° C under a pressure of 0.7 MPa abs carbon monoxide and hydrogen with a molar ratio of 1: 1. Then 1 mL 3-hexene from Example 1 was added and the mixture was left for a further 4 hours at 110 ° C. and a pressure of 0.7 MPa abs carbon monoxide and hydrogen with a molar ratio of 1: 1 for the reaction. The reaction vessel was then cooled, let down and the reaction mixture obtained was analyzed by gas chromatography. With a conversion of 42.5%, the selectivity to heptanals was 100% and the selectivity to n-heptanal was 92%.

Example 3B Oxidation of the mixture containing heptanal Example 3A

Oxidation of the heptanal mixture obtained in Example 3A can be carried out analogously to the description in Example 2B. According to the composition of the heptanal mixture thus a particularly high proportion of n-heptanoic acid can be obtained.

Example 3A shows that the use of the phosphorus chelate ligand A in the hydroformylation gave the corresponding linear, terminal alkanal n-heptanal with a selectivity of over 90%. Accordingly, a proportion of over 90% of n-heptanoic acid would also be obtained in Example 3B by the oxidation of the mixture. In contrast, the hydroformylation in the absence of the phosphorus chelate ligand A and using the amidated polyethyleneimine in Example 2A only leads to an n-heptanal selectivity of 22.8% and thus after the oxidation to a mixture of different C ₇ -carboxylic acids.

Example 4 Preparation of a mixture containing hexanoic acids Example 4A Hydroformylation of 2-pentene

500 g of 2-pentene from Example 1, 500 g of toluene, 31.3 mg of Rh (CO) ₂ (acac) (source: Strem), where acac stands for acetylacetonate, and 2.77 were placed in a 2.5 L autoclave g Polyethyleneimine, in which 60% of the amine groups were amidated with lauric acid and which was prepared in accordance with the "synthesis of amidated polyethyleneimine" described above. At room temperature, carbon monoxide and hydrogen were then introduced in a molar ratio of 1: 1 to a pressure of 18 MPa abs. The mixture was heated to 130 ° C., pressurized to 28 MPa abs with further carbon monoxide and hydrogen (molar ratio of 1: 1) and left under the conditions for 5 hours while maintaining the pressure and temperature. The autoclave was then cooled, decompressed and the discharge isolated. The discharge comprised a mixture containing n-hexanal, 2-methylpentanal and 2-ethylbutanal.

Example 4B Oxidation of the mixture containing hexanal Example 4A

42.8 g of the hexanals obtained from Example 4A containing The mixture was made up to 110 g with heptane, with potassium hydroxide to a calculated content of 0.5 wt .-% potassium hexanoate added and filled into a bubble column. Then was over a period of 20 hours at room temperature and Atmospheric pressure 20 NL / h air gas. A gas chromatographic analysis the discharge gave a yield of hexanoic acids of 98% a conversion of hexanals of> 99%.

Example 5 Preparation of a tridecanoic acid-containing mixture Example 5A Dimerization of 3-hexene

An isothermally heatable reactor with a diameter of 16 mm was treated with 100 ml of a catalyst comprising 50% by weight of NiO, 34% by weight of SiO ₂ , 13% by weight of TiO ₂ and 3% by weight of Al ₂ O ₃ (according to DE -A 43 39 713) filled as 1 to 1.5 mm grit and conditioned for 24 hours at 160 ° C under nitrogen. 3-Hexene from Example 1 was then passed through the reactor at a rate of 0.25 kg / Lh (WHSV) based on the reactor volume at a temperature of 120 ° C. The product obtained was fractionally distilled and a mixture containing dodecene was isolated. This contained 14.2% by weight of n-dodecene, 31.8% by weight of 5-methylundecene, 29.1% by weight of 4-ethyldecene, 6.6% by weight of 5,6-dimethyldecene, 9. 3% by weight of 4-methyl-5-ethylnone and 3.7% by weight of diethyl octene.

Example 5B Hydroformylation of the mixture containing dodecene from Example 5A

800 g of the mixture containing dodecene from Example 5B were placed in a 2.5 L autoclave. At room temperature, carbon monoxide and hydrogen were then introduced in a molar ratio of 1: 1 to a pressure of 10 MPa abs and heated to 130 ° C. The catalyst solution consisting of 195.5 g of toluene, 50 mg of Rh (CO) ₂ (acac) (source: Strem), where acac stands for acetylacetonate, and 4.5 g of polyethyleneimine, in which 60% of the amine groups were used, were then passed through a lock were amidated with lauric acid and which was prepared according to the "synthesis of amidated polyethyleneimine" described above. The mixture was then pressed to 28 MPa abs with further carbon monoxide and hydrogen (molar ratio of 1: 1), heated to 150 ° C. and left under the conditions for 5 hours while maintaining pressure and temperature. The autoclave was then cooled, decompressed and the discharge isolated. A gas chromatographic analysis of the discharge showed a yield of C ₁₃ oxo product (C ₁₃ aldehydes and C ₁₃ alcohols) of 92% with a conversion of dodecenes of> 95%. The discharge was then distilled in such a way that the C ₁₃ aldehydes (tridecanals) were obtained in pure form.

Example 5C Oxidation of the mixture containing tridecanals Example 5B

100 g of the C ₁₃ -aldehyde mixture obtained from Example 5B were admixed with potassium hydroxide to a calculated content of 0.5% by weight of potassium tridecanoate and filled into a bubble column. Subsequently, 20 NL / h of air were gassed in over a period of 20 hours at room temperature and atmospheric pressure. The discharge contained a mixture of tridecanoic acids.

Claims (9)

1. A process for the preparation of a saturated aliphatic C ₃ to C ₃₀ carboxylic acid or mixtures thereof, characterized in that 1-butene, cis-2-butene, trans-2-butene or a mixture thereof is used, a) optionally converted into a C ₂ -C ₂₉ alkene or a mixture thereof by metathesis and / or oligomerization; b) the 1-butene, cis-2-butene, trans-2-butene or its mixture and / or the C ₂ - to C ₂₉ -alkene or its mixture from the optional process step (a) by hydroformylation into a C ₃ - transferred to C ₃₀ alkanal or its mixture; and c) the C ₃ to C ₃₀ alkanal or its mixture from process step (b) is converted by oxidation into the saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture. 2. The method according to claim 1, characterized in that 1-butene, cis-2-butene, trans-2-butene or a mixture thereof is used, a) converted into a C ₂ -C ₂₉ alkene or a mixture thereof by metathesis and / or oligomerization; b) the C ₂ -C ₂₉ alkene or its mixture from process step (a) is converted by hydroformylation into a C ₃ -C ₃₀ alkanal or its mixture; and c) the C ₃ to C ₃₀ alkanal or its mixture from process step (b) is converted by oxidation into the saturated aliphatic C ₃ to C ₃₀ carboxylic acid or its mixture. 3. Process according to claims 1 to 2, characterized in that the 1-butene, cis-2-butene, trans-2-butene or its mixture in step (a) a) converted by metathesis into a C ₂ -C ₆ alkene or a mixture thereof; and b) the C ₂ to C ₆ alkene or its mixture is converted into a C ₄ to C ₁₃ alkene or its mixture by dimerization and / or trimerization. 4. Process according to claims 1 to 3, characterized in that the hydroformylation in step (b) in the presence of a carbon monoxide / hydrogen mixture and a metal complex compound homogeneously dissolved in the reaction medium comprising a metal from the 8th to 10th group of the periodic table and a polyethyleneimine, which units of the general formula (I) or branched isomers thereof


in which the sum of m + n is at least 10 and R each independently of one another is hydrogen, alkyl, cycloalkyl, aryl, aralkyl, acyl radicals having up to 30 carbon atoms or hydroxyalkyl (poly) oxyalkylene radicals having up to 500 Alkyleneoxy units mean, has, carries out. 5. Process according to claims 1 to 4, characterized in that the hydroformylation in step (b) in the presence of a carbon monoxide / hydrogen mixture and a metal complex compound homogeneously dissolved in the reaction medium comprising a metal from the 8th to 10th group of the periodic table and a phosphorus chelate compound of the general formula (II)


in the
Q is a bridge group of the formula


is what
A ¹ and A ² independently of one another represent O, S, SiR ^a R ^b , NR ^c or CR ^d R ^e ,
in which
R ^a , R ^b and R ^c independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,
R ^d and R ^e independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group R ^d together with another group R ^d or the group R ^e together with another group R ^{e form} an intramolecular bridge group D,
D is a double-bonded bridge group selected from the groups


is where
R ⁹ and R ¹⁰ independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are connected to one another to form a C ₃ -C ₄ -alkylene bridge,
R ¹¹ to R ¹⁴ independently of one another for hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, SO ₃ H, sulfonate, NE ¹ E ² , alkylene-NE ¹ E ² E ³⁺ X ^- , Acyl or nitro,
c is 0 or 1,
Y represents a chemical bond,
R ⁵ to R ⁸ independently of one another are hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, COOR ^f , COO ^- M ⁺ , SO ₃ R ^f , SO ^- ₃ M ⁺ , NE ¹ E ² , NE ¹ E ² E ^{3 +} X ^- , alkylene-NE ¹ E ² E ³⁺ X ^- , OR ^f , SR ^f , (CHR ^g CH ₂ O) _x R ^f , (CH ₂ N (E ¹ )) _x R ^f , (CH ₂ CH ₂ N (E ¹ )) _x R ^f , halogen, trifluoromethyl, nitro, acyl or cyano,
wherein
R ^f , E ¹ , E ² and E ³ each represent the same or different radicals selected from hydrogen, alkyl, cycloalkyl or aryl,
R ^{g represents} hydrogen, methyl or ethyl,
M ^{+ stands} for a cation,
X ^{- represents} an anion, and
x represents an integer from 1 to 120,
or
R ⁷ and / or R ⁸ together with two adjacent carbon atoms of the benzene nucleus to which they are attached represent a condensed ring system with 1, 2 or 3 further rings,
a and b independently of one another denote the number 0 or 1
and
R ¹ to R ⁴ independently of one another are hetaryl, hetaryloxy, alkyl, alkoxy, aryl, aryloxy, cycloalkyl, cycloalkoxy, heterocycloalkyl, heterocycloalkoxy or an NE ¹ E ² group, with the proviso that R ¹ and R ^{3 are} via the nitrogen atom are pyrrole groups bonded to the phosphorus atom P or wherein R ¹ together with R ² and / or R ³ together with R ^{4 is} a double-bonded group E of the formula Py-IW containing at least one pyrrole group bonded to the phosphorus atom P via the pyrrolic nitrogen atom, wherein
Py is a pyrrole group
I stands for a chemical bond or for O, S, SiR ^a R ^b , NR ^c or CR ^h R ⁱ ,
W represents cycloalkyl, cycloalkoxy, aryl, aryloxy, hetaryl or hetaryloxy, and
R ^h and R ⁱ independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,
or a bispyrrole group of the formula Py-I-Py bonded to the phosphorus atom P via the nitrogen atoms
forms,
performs. 6. The method according to claim 5, characterized in that the phosphorus chelate compound (II) is a compound of the general formulas (IIa), (IIb) or (IIc)


starts. 7. The method according to claims 1 to 6, characterized in that one uses as 4-butene, cis-2-butene, trans-2-butene or its mixture C ₄ raffinate II. 8. The method according to claims 1 to 7, characterized in that as saturated aliphatic C ₃ - to C ₃₀ carboxylic acid or mixtures thereof, pentanoic acid, 2-methylbutyric acid, n-heptanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-propylheptanoic acid , n-tridecanoic acid, iso-tridecanoic acid, neo-tridecanoic acid, 2-methyldodecenoic acid or mixtures thereof. 9. Use of the saturated aliphatic C ₃ - to C ₃₀ -carboxylic acid prepared according to claims 1 to 8 or mixtures thereof for the production of dyes, pharmaceutical and agricultural active ingredients, plastics and surfactants.